title: Infant iron status affects iron absorption in Peruvian breastfed infants at 2 and 5 mo of age.
abstract: BACKGROUND
  Effects of prenatal iron supplementation on maternal postpartum iron status and early infant iron homeostasis remain largely unknown.
  
  
  OBJECTIVE
  We examined iron absorption and growth in exclusively breastfed infants in relation to fetal iron exposure and iron status during early infancy.
  
  
  METHODS
  Longitudinal, paired iron-absorption (⁵⁸Fe) studies were conducted in 59 exclusively breastfed Peruvian infants at 2-3 mo of age (2M) and 5-6 mo of age (5M). Infants were born to women who received ≥ 5100 or ≤ 1320 mg supplemental prenatal Fe. Iron status was assessed in mothers and infants at 2M and 5M.
  
  
  RESULTS
  Infant iron absorption from breast milk averaged 7.1% and 13.9% at 2M and 5M. Maternal iron status (at 2M) predicted infant iron deficiency (ID) at 5M. Although no infants were iron deficient at 2M, 28.6% of infants had depleted iron stores (ferritin concentration <12 μg/L) by 5M. Infant serum ferritin decreased (P < 0.0001), serum transferrin receptor (sTfR) increased (P < 0.0001), and serum iron decreased from 2M to 5M (P < 0.01). Higher infant sTfR (P < 0.01) and breast-milk copper (P < 0.01) predicted increased iron absorption at 5M. Prenatal iron supplementation had no effects on infant iron status or breast-milk nutrient concentrations at 2M or 5M. However, fetal iron exposure predicted increased infant length at 2M (P < 0.01) and 5M (P < 0.05).
  
  
  CONCLUSIONS
  Fetal iron exposure affected early infant growth but did not significantly improve iron status or absorption. Young, exclusively breastfed infants upregulated iron absorption when iron stores were depleted at both 2M and 5M.
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY (JLF and KOO); the USDA/Agricultural Research Service Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX (SAA); and the Instituto de Investigación Nutricional, Lima, Peru (NZ).
authors.forename: Julia L
authors.initials: JL
authors.lastname: Finkelstein
authors.forename: Kimberly O
authors.initials: KO
authors.lastname: O'Brien
authors.forename: Steven A
authors.initials: SA
authors.lastname: Abrams
authors.forename: Nelly
authors.initials: N
authors.lastname: Zavaleta
mesh_terms: D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000453:epidemiology / Q000378:metabolism* / Q000517:prevention & control; D001827:Body Height; D001942:Breast Feeding; D002657:Child Development; D003300:Copper / Q000032:analysis; D019587:Dietary Supplements; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007223:Infant; D007408:Intestinal Absorption; D007501:Iron / Q000097:blood; D007503:Iron Isotopes; D019266:Iron, Dietary / Q000008:administration & dosage / Q000378:metabolism* / Q000627:therapeutic use; D008137:Longitudinal Studies; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D008895:Milk, Human / Q000737:chemistry; D009752:Nutritional Status; D010568:Peru / Q000453:epidemiology; D015995:Prevalence; D011990:Receptors, Transferrin / Q000097:blood; D055815:Young Adult
chemical_list: D007503:Iron Isotopes; D019266:Iron, Dietary; D011990:Receptors, Transferrin; D003300:Copper; D005293:Ferritins; D007501:Iron